Fasting breath hydrogen concentration in short bowel syndrome patients with colon incontinuity before and after antibiotic therapy

Noninvasive Measurement of Transit Time in Short Bowel Syndrome

BACKGROUND

Patients with short bowel syndrome (SBS) have limited absorption of nutrients, in part because of the rapidity with which chyme passes through the bowel. We sought to evaluate noninvasive measurements of intestinal transit time to aid in research questions where transit is measured repeatedly.

METHODS

Three methods were compared in 8 patients with SBS: the time for blue food color to appear in ostomy effluent or stool, lactulose breath hydrogen testing, and the first radiopaque ring from a capsule in timed stool samples.

RESULTS

Median blue dye fasted transit was 96.3 minutes, with breakfast was 117.3 minutes, and with lactulose was 72 minutes. By breath hydrogen testing, transit time was 52.5 minutes but detectible in only 5 of 13 tests. Transit time by radiopaque marker was 967 minutes, but no markers passed in 7 of 14 tests.

CONCLUSIONS

Visualization of blue food color in ostomy effluent is a simple, inexpensive approach that can be applied to fasted subjects or after specific meals. Breath hydrogen testing should only be applied in the rare patient with SBS who has an intact ileocecal valve. Radiopaque markers are less useful, most likely because they become trapped due to anatomic changes.

Management and Complications of Short Bowel Syndrome: an Updated Review

Short bowel syndrome (SBS) is defined as loss of bowel mass from surgical resection, congenital defects, or disease. Intestinal failure (IF) includes the subset of SBS unable to meet nutrition needs with enteral supplements and requires parenteral nutrition (PN). The parenteral treatment of SBS is now a half-century old. Recent pharmacologic treatment (GLP-2 analogues) has begun to make a significant impact in the care and ultimate management of these patients such that the possibility of reducing PN requirements in formerly PN-dependent patients is a now a real possibility. Finally, newer understanding and possible treatment for some of the complications related to IF have more recently evolved and will be an emphasis of this report. This review will focus on developments over the last 10 years with the goal of updating the reader to new advances in our understanding of the care and feeding of the SBS patient.

Colonic energy salvage in chronic pancreatic exocrine insufficiency

BACKGROUND

Chronic pancreatic exocrine insufficiency results in maldigestion. As a result, increased amounts of undigested nutrients reach the colon, providing more substrate for bacterial fermentation to produce short-chain fatty acids, which could therefore provide additional energy supplement.

METHODS

This study aimed to assess carbohydrate malabsorption in patients with chronic pancreatic exocrine insufficiency after ingestion of a standard diet and to calculate energy salvaged by colonic bacterial metabolism. A 72-hour stool collection was done on 10 adult patients receiving a 3-day standard diet containing 100 g fat, 329 g carbohydrate, and 154 g protein, and short-chain fatty acids, fat, carbohydrate, and nitrogen excretion were assessed. A breath hydrogen test after ingestion of 200 g (dry weight) cooked maize meal (test meal) and 10 g oral inulin (standard), respectively, was subsequently done on the patients and 15 healthy adult controls.

RESULTS

Breath hydrogen production after ingestion of maize meal and inulin, respectively, and calculated carbohydrate malabsorption were significantly greater in patients (21.4% +/- 17%) than in controls (10.2 +/- 1.4%; p < .05). Patients malabsorbed 70.4 g/d (281.6 kcal) carbohydrate in the standard diet. Total carbohydrate loss in stool amounted to 8.1 g/d (2.4%), and 62.3 g/d (19%) was hence salvaged as short-chain fatty acids for energy provision. Colonic bacterial fermentation therefore converted 88.5% of malabsorbed carbohydrate to short-chain fatty acids, 92.8% of which was absorbed and 7.2% excreted. This suggests that 10.2% of energy expenditure/requirement in these patients is derived from salvage of malabsorbed carbohydrate.

CONCLUSIONS

Colonic bacterial metabolism is a significant source of energy salvage in patients with pancreatic enzyme deficiency.

Small intestinal bacterial overgrowth: roles of antibiotics, prebiotics, and probiotics

Small intestinal bacterial overgrowth is common in intestinal failure. Its occurrence relates to alterations in intestinal anatomy, motility, and gastric acid secretion. Its presence may contribute to symptoms, mucosal injury, and malnutrition. Relationships between bacterial overgrowth and systemic sepsis are of potential importance in the intestinal failure patient because the direct translocation of bacteria across the intestinal epithelium may contribute to systemic sepsis: a phenomenon that has been well established in experimental animal models. The accurate diagnosis of bacterial overgrowth continues to present a number of challenges in clinical practice and especially so among patients with intestinal failure. The management of patients with bacterial overgrowth remains, for the most part, primarily empiric and comprises antibiotic therapy and correction of any associated nutritional deficiencies. Although evidence from experimental animal studies consistently indicates that probiotics exert barrier-enhancing, antibacterial, immune-modulating, and anti-inflammatory effects, which all could be benefits in small intestinal bacterial overgrowth and intestinal failure, their role in human beings remains to be evaluated adequately.